Apparatus for making butt welded tubes and pipes



Jan. 16, 1934. H. MAYWEG 1,944,095

APPARATUS FOR MAKING BUTT WELDED TUBES AND PIPES Original Filed June 1, 1927 4 Sheets-Sheet 1 I Jan. l6, T934-. MAYWEG 1,944,095

APPARATUS FOR MAKING BUTT WELDED TUBES AND PIPES Original Filed June 1, 1927 4 Shets-Sheet 2 M g6 attozwuzd Jan. 16, 1934. H MA W 1,944,095

APPARATUS FOR MAKING BUTT WELDED TUBE AND PIPES Original Filed June 1, 1927 4 Sheets-Sheet 3 Jan. 16,1934.

H. MAYWEG APPARATUS FOR MAKING BUTT WELDED TUBES AND PIPES Original Filed June 1, 1927 llllllllll IIIIIIIH 4 Sheets-Sheet 4 UNITED STATES APPARATUS FOR MAKING BUTT WELDED TUBES AND PIPES Hugo Mayweg, Holzwickede, Germany, assignor, by mesne assignments, to Laura S. Stevenson,

Wheeling, W. Va.

Application June 1, 1927, Serial No. 195,690 Renewed February 1, 1933 7 Claims.

The invention relates to the making of butt joined tubes and pipes, and has for its prime object to provide an improved method and apparatus for the continuous production of a tubular shape from a single blank which is first subjected to a series of operations and thereby formed into a tube with the edges of the blank in abutted relation, immediately after which the abutted edges of the blank are electrically joined, the finished tube being subsequently straightened and cut into lengths. The tube is fed to and through the electric apparatus by means of the traveling movement imparted to the tube by the action of the rolls employed in shaping the blank into tubular form, and the capacity of the electric apparatus is such as to produce an eflicient joint at the rate of speed imparted to the tube by the rolls of the tube forming machine or apparatus.

The present invention is particularly designed for the manufacture of thin wall tubing, and it is an important feature of the present invention to obtain a large contact area on the tube during the electric operation.

The invention has been illustrated in the accompanying drawings wherein,

Figure 1 is a side elevation, more or less diagrammatic of a tube shaping and joint forming apparatus embodying the features of the present invention;

Figure 2 is a cross sectional view of a tube blank having its longitudinal edges bevelled by theflrst pass of the tube forming machine;

" Figure 3 is a similar view showing the plate I having its bevelled edges bent into flanges projecting at that side of the blank which is to be the exterior of the tube;

Figure 4, 5, 6, '7 and 8 are views of the blank in its successive stages offormation;

Figure 9 is an enlarged cross sectional view of the form of electric apparatus employed in the present invention:

Figure 10 is a detail sectional view on the line 10-10 of Figure 9.

Figures 11 and 12 are enlarged fragmentary views showing the cooperative relation between the seam of the tube and one of the electrodes of the electric apparatus.

Fig. 13 is a detailed plan view illustrating the mounting of the means for reciprocating the upper electrode roll,

Fig. 14 is a side elevation of Fig. 13.

The apparatus of the present invention includes a tube shaping or forming apparatus designated in general by the reference character A, and an electric apparatus designated in general by the reference character B, the two machines being arranged in close proximity to one another'so that the electric machine may receive the tubular shape immediately as it is fed from the tube shaping machine. The tube making machine is provided with pairs or sets of cooperating rolls for performing the successive bending or shaping operations upon the blank, and said rolls are arranged to produce the successive passes which have been designated 2, 3, 4, 5, 6, '7 and 8, through which the blank is continuously fed and shaped to the final product.

In order that the operation may be a continuous one, it is proposed to have the tube blank C put up in a roll or coil D which is mounted upon a suitably supported reel E. Located between the reel E and the feedin end of the tube shaping machine A, there is a suitable track 10 supported in a horizontal position in any suitable manner as upon leg standards 11. The track 10 is below the horizontal line of the passes of the tube shaping machine and supports a carriage 12 mounted to travel back and forth on the track and beneath the horizontal line of the passes. Suitable clamping devices 13 and 14 are provided upon the carriage so as to clamp thereupon the rear end of one tube blank and the front end of another tube blank with said ends in abutted relation so that they may be welded by any suitable means, as for instance by a gas torcn 15 carried by the carriage. It will ofcourse be understood that any form of welding means may be employed as the form of the welding means constitutes no part of the present invention. The clamps 13 and 14 are hand operated, and are manually released just before the carriage reaches the end of the track adjacent the tube forming machine, and the carriage is returned to its original position by a weight 16 and a cord 17 connected to the carriage and traveling over a guide pulley 18.

As the tube blank C travels through pass 2, itslongitudinal edges are provided with the bevels 19 as shown in Figure 2. Immediately upon being fed out of the pass designated 2, the bevelled tube blank is fed into the pass designated 3 and its beveled edges bent into flanges 20, as shown in Figure 3, said flanges being projected at the lower side of the blank which is to be the exterior of the finished tube in its final form.

The succeeding passes 4, 5, 6, 7, and 8 shape the blank progressively in accordance with Figures 4, 5, 6, '7 and 8 of the drawings. It will therefore be understood that' as the blank emerges from the last pass designated 8 it will have been bent into the tubular shape C shown in Figures 8 and 9 with its bevelled edges 19 in partially abutted relation and the flanges 20 disposed longitudinally of the tube on the exterior thereof. The bevelled or inclined edges 19 of the blank do not abut throughout their widths, but come together at their outer end portions only, thereby leaving a substantially V- shaped space between the abutted edges of the blank at the inner side of the tube. The two flanges 20 constitute an external rib extending longitudinally of the tube and of V-shape in cross section. It will here be noted, as best shown in Figure 11 of the drawings, that the widest dimension a of the combined ribs or flanges 20 at the exterior of the tube is less than the thickness b of the blank for an important purpose as will be hereinafter explained.

Immediately after the tubular shaped blank emerges from the last pass 8, it is subjected to the action of the electric machine for the purpose of fusing the external rib, so that fused portions thereof may flow downwardly and fill the gap between the lower portions of the spaced edges 19 of the blank and thereby joining such edges in a joint in a simple and eflicient manner. The tubular shape is fed to the electric apparatus by reason of the travel of the blank through the tube forming machine, whereby the tube forming machine and the electric machine operate successively and continuously upon a single blank as it is travelling through the apparatus under the feeding effect of the driven rolls of the tube forming machine.

The tubular shape C, in the cross sectional shape shown in Figure 8, travels from the last pass -8. of the tube forming machine into the electric machine, under the influence of the feedmg action of the tube forming machine, and is received upon a work receiving electrode roll 21 carried by a shaft 22 mounted in opposite bearings 23 rising from mercury cups 24 supported by standards 25 rising from the opposite ends of a cross head 26 bolted or otherwise secured to one of the pole pieces 27 of a secondary 28 of any desired form of electric generator. Each end of the shaft 22 is provided with a circular head 29 disposed to rotate in the mercury bath in the adjacent mercury cup, and the periphery of the head is provided with an annular groove 30 to increase the contact surface of the head with the mercury.

Disposed transversely across the top of the elec trode roll 21 is an electrode shaft 31 provided at its middle with a band or collar 32, preferably of copper and disposed so as to come into proper cooperative relation with the rib on the exterior of the tubular shape C supported by the electrode roll 21. Each end of the shaft 31 is mounted in a bearing 33 carried by and insulated from a substantially horizontal arm 34, see Figure 10, the arm being pivotally supported at one end as at 35. Each end of the shaft 31 is provided with a circular head 36 mounted to rotate in a mercury cup 37 carried upon the upper end of a standard 38 rising from a cross head 39 bolted or otherwise secured to the other pole piece 40 of the electric generator.

It is proposed to longitudinally reciprocate the electrode roll 31 so as to work the band or collar 32 transversely across the rib on the tube and thereby prevent the wearing of a groove in the periphery of the part 32. To accomplish this result, the arms 34 are pivotally carried at the ends of a rock-shaft in upstanding brackets 51 rising from a base member 52 mounted to slide endwise in a guideway 53 provided upon the top of the frame portion 54 of the apparatus.

It will, of course, be understood that the electrode shaft 31 has its ends mounted in the insulated bearings 33 carried by the arms 34, and thus the electrode roll is entirely free for up and down movement and is capable of gravitating into engagement with the upstanding rib on the work-piece so as to bear its weight against it and follow any irregularities therein.

To limit downward movement of the electrode roll, when there is no work-piece in the apparatus, there is provided a projection 55 depending upon one of the arms 34 and designed to engage a stop member shown in the accompanying drawings as a seat screw adjustable through a threaded opening in a boss 56 provided upon the adjacent bracket 51.

To reciprocate the upper electrode in the direction of its length, there is provided an oscillating arm 57 fulcrumed as at 58 upon the frame part 54 and connected at one end by means of a pivotal link 59 with the base member 52. The outer end of the arm 57 is slotted at 60 to receive a wrist pin 61 carried by an eccentric 62, mounted upon the frame part 54 and suitably driven from some operating part of the general apparatus.

The electrode roll 21 is embraced by a pair of rim members 41 and 42 in the form of rings, which rings are adjustably secured together by a plurality of headed and screw threaded fastenings 43 which extend through openings in the rings, the openings in one of the rings being screw threaded. The roll member 21 is provided adjacent its periphery with a series of armate slots 44, and an open ended screw threaded opening 45 extends through each slotted part and is longitudinally tapered and receives a tapered screw threaded plug 46, whereby the periphery of'the roll 24 may be expanded at the slotted portions so as to firmly maintain the rim members 40 and 41 upon the roll member 21. By this construction, the rim members may be replaced when worn or damaged in a simple and efficient manner.

After passing from the electric machine, the joined tube C passes through a finishing and straightening machine F of any ordinary or preferred form. As shown in Figure 1 of the drawings, the machine F includes finishing rolls 47 for smoothing the exterior of the pipe, and bending rolls 48 for straightening the tube or pipe. After passing from the finishing and straightening machine F, the tube or pipe is run into any desired form of tube cutting machine, not shown, for the purpose of cutting the finished tube into lengths.

In the beginning of the joining operation, the pole or electrode member 32 rests upon the apex of the pointed external rib 20 on the tubular shape C, whereby the tip edge of the rib be comes fused and the pole piece 32 sinks down into the rib to about the position shown in Figures 11 and 12 of the drawings, whereby the rib will be fused throughout substantially its entire depth as the tubular shape is fed through the machine under the feeding influence of the driven rolls of the tube shaping machine A. Under operating conditions, the weight of the pole piece 32 and its associated parts is supported upon the tubular shape or work piece C, as shown in Figures 11 and 12, and as the latter is supported in the seat of the electrode roll 21 there is no pressure exerted to force the spaced edges of the blank together such as is commonly employed in welding operations. The pole member 31 will be rotated by reason of the frictional engagement between the tubular shape C'and the pole piece 32, while at the same time the pole member 31 will be reciprocated transversely across the rib. It will of course be understood that thesize of the mercury cups 37 is sufficient to permit of the necessary lateral play of the contact head 36 in the mercury baths. As the rib 32 is fused, the molten metal runs down and fills the gap between the spaced edge portions 19 of the blank thereby producing a strong and durable joint without resulting in any internal rib on the completed tube while at the same time filling the gap between the edges of the blank without leaving a groove at the interior of the tube. a

It will here be explained that there is no welding of the-joint in the sense of softening metal members and then applying premre thereto sufficient to unite the softened parts into a welded joint, for the reason that the fused parts of the flanges gravitate into the gap which is filled by the fused metal, and such fused metal when it hardens unites the edges of the blank in a strong and durable seam or joint.

The large dimension a of the combined flanges 20, is best shown in Fig. 11, is less than the thickness b of the blank or the wall of the tube, where by, the electric current is concentrated in the flanges or rib and fusion is limited thereto and burning of the walls of the tube adjacent the butt weld is effectually prevented.

Inthe practice of the invention, and in order that it may be continuous, the tube blank C is in the form of a long strip of the desired thickness and width. For convenience in handling, the strip is wound into a coil D, Figure 1, and mounted upon the reel E. The feed end of the strip or blank is fed to the roll forming machine A and entered by hand into the bite of the driven rolls constituting the first pass designated 2, and thereafter the blank is fed automatically through the tric machine and passes into the peripheral seat defined by the rim members 41 and 42 of the electrode roll 21, the external rib 20 of the shape being in engagement with the electrode or pole piece 42, as best shown in Figure 9 of the drawings. Fusion and joining takes place in the electric machine, as hereinbefore described, and thereafter the joined tube C passes on to the finishing and straightening machine F and thence to a tube cutting machine, not shown, for the purpose of cutting the completed tubes into lengths.

From the foregoing explanation of the practice of the present invention, it will be understood that the tube shaping and the butt joining operations are performed successively and continuously upon the same strip of metal, and that the work emerges from the finishing and straightening machine in a smooth finished condition and is afterwards cut into lengths. The finished tube has neither external projections nor internal grooves.

edge of the rib is obtained, which permits of the.

joining of the seam as rapidly as the shape C can be formed by the tube forming machine A and fed thereby to the electric joining machine. This rapid electric joining of the seam permits of the joining operation following immediately upon the completion of the final step of the tube shaping operations, and therefore permits the opera tion of the tube shaping machine at its normal rate of speed. In actual practice, tubes have been made in accordance with the present invention at the rate of twenty feet per minute.

As hereinbefore explained overheating at the joining point is prevented because of the triangular shape of the external rib 20, together with the fact that the width of the base of the rib is less than the thickness of the blank, so that the electric current is concentrated in said rib and therefore burning of the blank adjacent the joint is impossible. Actual practice has shown-that even great irregularities in the thickness of the blank or metal strip have no undesirable influence upon the formation of the joint, and therefore it is possible to use crude or so called hot rolled metal strips which are seldom uniform in their dimensicns. Moreover the electric current consumption is low, as the heat is concentrated at the joining zone.

A very important feature of the present invention resides in obtaining a large contact area between the tubular shape and one of the electrodes, and this feature will be best understood by reforence to Figures 8 and 9 of the drawings. It will be remembered that Figure 8 discloses the cross section of the shape as it leaves the last pass 8 of the tube shaping machine. In the manufacture Ill of thin wall tubing, for which the present invention has been particularly designed, the tubular shape may be given the substantially elliptical cross section, shown in Figures 8 and 9, with opposite side walls substantially straight throughout a large portion of their lengths and converging in a direction away from the butt joint. It is while the tubing is in this shape, that the joining takes place, and, as best shown in Figure 9, it will be seen that the inner faces or walls of the rings 41 and 42v are straight and converge inwardly so as to define a seat in which the substantially straight side walls of the tubular shape will contact throughout their lengths with the correspondingly shaped inner walls of the seat defined by the rings 41 and 42, whereby the maximum contact is obtained between the tubular shape and the electrode which supports the shape. -Moreover, the weight of the electrode roll 31 presses and holds the shape snugly in the seat of the electrode roll 21. After the joining operation, the more or less elliptical shape is brought to a circular shape by the finishing and straightening machine F.

What I claim is:

1. In an electric device, the combination of an idle electrode roll mounted upon a horizontal axis and provided with an external peripheral groove constituting a seat for the reception of a tubular work piece, another idle electrode roll of the opposite polarity mounted upon a horizontal axis and disposed transversely across the top of the first mentioned roll in position for engagement with a tubular work piece in the seat of the first mentioned electrode roll, and means for reciprocating said other electrode roll transversely across the first mentioned electrode roll.

2. In an electric device, the combination of an idle electrode roll mounted upon a horizontal axis and provided with contact heads, mercury cups of the same polarity receiving the re spective contact heads, the electrode roll having an external peripheral groove constituting a seat for the reception of a tubular work piece, another idle electrode roll mounted for reciprocation upon a horizontal axis and disposed transversely across the top of the first mentioned electrode roll in position for engagement with a work piece in the seat of said first mentioned roll, contact heads for the second mentioned roll, and mercury cups receiving the respective contact heads of said other electrode roll and of the opposite polarity from that of the first mentioned mercury cups.

3. In an electric device, an electrode roll, a pair of rings embracing the periphery of the roll in electric connection therewith and with each other and spaced to define a seat for the reception of a tubular work piece, and means for detachably securing the rings to the roll.

4. In an electric device, the combination of an electrode roll, a pair of rings embracing the roll and spaced to define a seat for the reception of a tubular work piece, the roll being provided with a series of arcuate slots adjacent the periphery thereof, there being a tapered screw threaded opening extending through each slotted portion of the roll, and a tapered expanded screw for each screw threaded opening. I

5. In an electric device, the combination of an idle electrode roll mounted upon a horizontal axis and provided with an external peripherai groove constituting a seat for the reception of a tubular shape, another idle electrode roll of the opposite polarity mounted upon a horizontal axis and disposed transversely across the top of the first mentioned roll in position for engagement with a tubular shape in the seat of the first mentioned electrode roll, said other electrode roll being mounted for endwise reciprocation.

6. In an electric device, the combination of a lower electrode roll mounted upon a horizontal axis, said roH having an external peripheral groove constituting a seat for a tubular work piece, the walls of the seat being substantially straight and converging inwardly, an upper electrode roll of the opposite polarity disposed transversely with respect to the lower electrode roll, vertically movable supporting arms for the upper electrode roll, each arm being pivotally supported on a substantially horizontal axis and provided with an insulated bearing for the upper electrode roll, the arms being free to gravitate and permit the upper electrode roll to bear its weight upon and follow irregularities in the workpiece, and stop means for limiting gravitation of the upper electrode roll when there is no workpiece in the apparatus.

7. In an electric device, the combination of a lower electrode roll mounted upon a horizontal axis, said roll having an external peripheral groove constituting a seat for a tubular work piece, the walls of the seat being substantially straight and converging inwardly, an upper electrode roll of the opposite polarity disposed transversely with respect to the lower electrode roll, means for supporting the upper electrode roll and permitting the same to gravitate into contact with the work-piece and to i'ollow irregularities therein, and stop means to limit the gravitation of the upper electrode roll when there is no work-piece in the apparatus.

HUGO MAYWEG.

. CERTIFICATE OF CORRECTION.

Patent No. l, 944, 095.

January 16, 1934.

HUGO MAYWEG.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 84, strike out the word "joining";

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 20th day of February, A. D. 1934.

(Seal) F. ii. Hopkins Acting Commissioner of Patents. 

